Solar jets are occasionally associated with the large scale solar filament eruptions ([1]}; [2]}). Solar filaments are dense and cool material
suspended in the hot solar corona along PILs. They are found to be in magnetic dip regions.
There are two main magnetic configurations for filaments namely sheared arcade and FR. In the sheared arcade configuration, the arcade connects the opposite polarities on
either sides of a PIL, whereas in the case of the FR configuration the magnetic field has helical magnetic
structure. Several models have been proposed for the solar eruptions ([3]}; [4]}; [5]}; [6]}).
Catastrophic loss of equilibrium or torus instability is the
important mechanism for the solar eruptions ([7]}; [8]}; [9]}).
In these models, it is assumed that the overlaying magnetic field (B\(_{ex}\) ) decreases with the increase of the
height (z)
from the photosphere i.e. B\(_{ex}\)  \(\propto \)  z\(^{-n}\) . The FR becomes unstable when the
decay index `n' at its location becomes less than
a critical value. According to simulations this value ranges from 1.3 to 1.75
([10]}; [11]}; [12]}; [13]}). Using different observations including high resolution SDO data and
multi–view STEREO observations it was found that this value lies between 1 and 1.5 in observed eruptions
([14]}; [15]}; [16]}; [17]}).
In addition to failed, partial and full filament eruptions, recently two filament eruptions were observed with the
quasi-equilibrium state in the middle part of a two-step process ([18]}; [19]}). In these cases the filament
starts to erupt and after attaining
some height it decelerates, stops and seems to be stable for some time. In case of [18]} this time was
rather short i.e. \(\sim \)  one hour and for the case of
[19]} the time was 15 hrs. Such cases are very crucial and play an important role in
understanding the Sun–Earth connections.
